The centerpiece of the upgrade kits is a rapid engine change-out system, reducing the time it takes to swap out an engine from up to 10 hours to less than 20 minutes. Simplifying engine replacement translates to less mechanical training needed and fewer tools. An extended range kit adds two 25 gallon tanks in the rear wheel wells and a 35 gallon main tank to extend the range of the Hummer to 1450 kilometers; or up to 1600 kilometers with fuel efficiency improvements. For more space, there's a body rework kit to allow soldiers over 6 feet 5 inches tall to sit in the front or rear for a 72 hour mission, along with web seats for more leg and headroom and to accommodate soldiers wearing body armor. More space makes the process of getting in and out of the vehicle quicker. Future improvements on the body rework include common seats with simplified attachments for quicker under-seat access. There are provisions for a cooling package to be used with liquid-cooled garments with plans for an integrated electric air conditioning unit for hot climates.
An auxiliary power unit (APU) is integrated into the concept design to power radios, computers, and cooling without having to run the engine. Further, many of the components of the concept Hummer will be electrically driven, including fans, power steering, water and fuel pumps, and the tire inflation system, reducing the number of belts needed. Fewer belts simplifies engine change-out and increases reliability. Ultimately, all belts will be eliminated. Finally, the Concept Hummer incorporates five point shoulder/lap belts, a digital dashboard, an integrated commander's computer, an anti-collision system, and integrated armor for better protection of vehicle systems and the solders in them. Over 175,000 Hummers have been produced to date and are in service around the world. Doug Mohney
The U.S. Army's National Automotive Center has unveiled a Concept HMMWV ("Hummer" in grunt-speak). This vehicle is an update of the existing 20 year old design, to create extended range, increased space for troops, and faster maintenance. A number of different retrofit kits have been designed to implement features on existing vehicles for more power and better performance.